Ctjt-ofe valve for steam-engines



FFC.

FREDERICK PERRY, OF NEVARK, NEW' JERSEY.

CUT-OFF VALVE FOR STEAM-ENGINES.

Specification of Letters Patent No. 13,359, dated July 31, 1855.

To all whom it may concern.'

Be it known that l, FREDERICK PERRY, of Newark, in the county of Essex and State of New Jersey, have invented a new and useful improvement in Detached Cut-Uff Valves for Steam-Engines, being the kind of valves so called as they are carried back and forth by the main valve they lie upon it, their movements being regulated by stops which determine the distance they are to move, each outer pair of stops being stationary, while the inner ones are movable, so as to graduate and determine the amount of steam to be cut off.

rl.`he nature of my improvement consists in substitut-ing steam pressure for holding the cut-off valves to their seatsA on top of the main valve instead of using springs as heretofore. Said springs are unreliable and often deranged, as they by constant pressure loose their set, and are also weakened by heat, and as they depend upon their rubbing surface to act against, it wears away and lessens their control over the valves. As soon as this is lost sufficient for the steam to move the valves as it rushes toward the port, it is apt to do it and throw them out of time, deranging the steam in its entrance through the main valve and affecting the piston injuriously. Sometimes the springs break or otherwise lose their control over the valves leaving them free to slip about and confuse the whole performance of the steam, besides involving more expense in making and applying them than my improved plan. Steam pressure is always in time and graduated according to its pressure it controls the valves to a certainty and as wanted, is not subject to failure in any way after the arrangement is properly fitted.

To enable others skilled in these matters to make and use my invention, I do hereby declare thatI the following is a full, and exactdescription thereof, reference being had to the accompanying drawings making a part of this specification, and to the letters of reference marked thereon, in which- Figure l is a perspective view of the ordinary steam chest and Valve-rod in general use for horizontal engines, and is detached from the cylinder, as it contains the improvement referred to; the other parts of the engine being as usual are not shown here; Fig. 2, a longitudinal vertical section through the center of the chest, and internal apparatus of valves, steam-ports and small sunk-channels in-the to their attachments, showing a part of my improvement; Fig. 3, a bed-plan of the chestand internal improvements having the cover removed; Fig. 4, a transverse sectional elevation across the center of the chest and its internal arrangements; Fig'. 5, al bed-plan of the cut olf and main valves, the former resting upon the face of the main valve; Fig. G, a bed plan of the main valve'showing the steam ports and a part of my improvement; Fig. 7, a bed plan of the expansion and contraction plates with their attachments, their ends broken off, the shape of the. ends being shown in the detached Fig. 7; ltig. S, a vertical view of the expansion and contraction plates and their attachments, and Fig. 9, a bed-plan of the links connecting the expansion plates to the eccentric wheels attached to the spindle.

Like letters refer to like parts throughout the drawings.

A A is the steam-chest made in the usualir way; B B, the main-valve which has double ports for admitting the steam into its top and terminating in a single port at the bottom of the valve to match the valve port in the bottom of the steam-chest. It also contains its exhaust port and my improvement.

C C is the detached cut off valves having corresponding double ports to match those in t-he main valve, and suitable stops for determining the distance the valves shall travel. D D are the expansion and contraction plates for graduating the movement of the cut-off valves, as their graduation is all made at the inside edge of the cut-oif valves, as the outer edge travels the same distance outward in all cases. The variation of the distance the cut-off valves are to move in cutting off the steam, is the distance at which the valves stop in approaching each other always stopping outward the same distance. These expansion plates have suitable stops to match those on the cut-off valves. They are connected with suitable links to the eccentric wheels attached to a spindle extending outside of the chest to operate these plates. E E is the steam chest valve seat with the steam ports between.

a a is myY improvement consisting of two face of the main valve, being long in line with the steamports and narrow transversely. Over these channels are placed the cut-off valves constantly covering them. rlhe valves sliding over the channels'are regulated by their stops b striking the stops c c on the expansion plates in their inward motion, and the stops d d on the ends of the grooved guides for the outward motion. These stops are stationary as the cut-off valves move outward the same distance in every instance. e e is the groove for guiding the expansion plates in their inward and outward motions in presenting their stops c c to determine the amount of cutting-off the steam.

f f are the slides cont-aining the groove. They are attached to the side of the steamche'st or to any other suitable object.

g g are the eccentric wheels which are embraced by the links connecting the expansion plates with the eccentrics.

7L is the spindle extending up through the steadying bar z' z' and top of the steam chest to receive a lever or crank to work the spindle. To this lever a suitable connect-ing rod is attached and extending to the governor attachments by which the cut-off valves are governed and all becomes self-acting cutting olf the steam as desired.

The governor regulates the cut-olf according to the demand of the work and dispensing with its connection with the throttlevalve as heretofore, making the governor the regulator in cutting off the steam.

j j are the links for connecting the eccentrics and expansion plates.

7c 7c are the steam ports through the cutoff valves; Z Z are the steam ports in the top of the main valve extending downward and uniting in one port atl at each end of the valve which match the admitting and dismissing ports; m m is the steam chest valve seat; n is the exhaust steam port. These ports and the chamber 0 in the main valve are all made and connected as usual, p p are holes extending from the channels d Z down into the exhaust portsin the main valve. By this arrangement these chambers are kept free of steam should any enter the same from the steam-chest. As the exhaust port opens outward and frees the engine of steam of course it frees the channels also.

g is the valve-rod extending from the valve to the eccentric on the main shaft of the engine.

g is the nut to the valve-rod.

1" is the gland or stuffing-box around the valve-rod.

The channels d Z should be no larger than will secure the cut-off valves from slipping, as too large channels allow too much pressure on the valves, making too much friction. 1f made small at first they can easily be enlarged if necessary:v As they are long they hold the valves parallel to the ports, which is important as varying from a parallel line is apt to cause the end corners to catch by skewing, besides interfering with/the steam in its entrance to the main valve ports.

lVhat- I claim as my invention and desire to secure by Letters Patent isrIhe combination of the channels d Z and holes p 79 with the cut-olii1 valves D D and exhaust recess o, as described or their equivalents for the purposes herein set forth or any other purpose for which they are suitable, merely modifying the parts to suit circumstances while the principles involved are the same.

FREDERICK PERRY. Vitnesses JOHN H. TIMs, WILLIAM H. BURNET. 

